#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<ll,ll> P;
typedef vector<ll> VI;
typedef vector<VI> VVI;
const ll MOD = 1000000007;
const ll INF = 1e18;
#define REP(i,n) for(int i=0;i<n;i++)
#define ALL(v) v.begin(),v.end()

int main(){
    string s; cin >> s;
    REP(i,26){
        if(s[i]-'a'!=i){
            cout << (char)('a'+i) << "to" << s[i] << endl;
            break;
        }
    }
    return 0;
}